Method for controlling spinning stroke of washing machine

ABSTRACT

A method for controlling a spinning stroke of a washing machine is disclosed. The method for controlling a spinning stroke of a washing machine comprises steps of: judging a first value of the laundry amount based on a frequency of water re-supply counted in a rinsing stroke; measuring the time taken for a drum rotating before a spinning stroke to reach a preset speed once a rinsing stroke is completed; judging a second value of the laundry amount based on the measured time; determining a final value of the laundry amount based on the first and second value of the laundry amount; and starting a spinning stroke based on the spinning condition determined based on the final value of the laundry amount. An object of the present invention is to provide a method for controlling a spinning stroke of a washing machine, in which the laundry amount is sensed more accurately in a spinning stroke.

This application claims the benefit of the Patent Korean Application No. P2005-16877, filed on Feb. 28, 2005, which are hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a washing machine, more particularly, to a method for controlling a spinning stroke of a washing machine based on an amount of laundry.

2. Discussion of the Related Art

In general, a washing machine is an appliance used in a house most commonly, which washes clothes, cloth item, articles of clothing and beddings (hereinafter, the laundry) and removes dirt of the laundry by using impact of water, chemical action of detergent and friction force between water current and the laundry.

A washing machine is classified into a pulsator type washing machine and a drum type washing machine. The pulsator type washing machine has a drum standing vertically, and the drum type washing machine has a drum standing horizontally.

Commonly, in a washing stroke, dirt on the laundry is removed by physical action of a drum as well as chemical action of detergent after water and detergent are mixedly supplied.

Hence, once used washing water is discharged outside after a washing stroke, a rinsing stroke starts in that washing water not mixed with detergent is supplied for rinsing detergent as well as dirt on the laundry.

After a rinsing stroke, a spinning stroke starts for dehydrating the laundry by means of centrifugal force generated from a rotating drum.

The spinning stroke is classified into an initial spinning stroke in that a drum rotates at a low speed and a main spinning stroke in that a drum rotates at a high speed for dehydrating the laundry.

First, in an initial spinning stroke, the amount of the laundry is sensed for adjusting an appropriate balance condition of a driving system in a washing machine to provide against unbalance as well as vibration of a drum.

The amount of the laundry is sensed before a main spinning stroke starts, because a range of the laundry distribution within a drum may be varied based on the amount of the laundry while rotating a drum and acceleration gradient having an effect of distributing the laundry at most may be varied based on the amount of the laundry.

A method of sensing the laundry amount is measuring the time taken for a drum to reach at a preset speed.

That is, the more amount of the laundry there is, the loner time it takes for a drum to reach a preset speed. Thereby, the laundry amount may be judged by how much time it takes for a drum to reach a preset speed.

When rotating a drum, acceleration gradient of spinning speed is applied variously based on the laundry amount sensed in a step of sensing the laundry amount for maximizing an effect of laundry distribution. A rotation speed of a drum is gradually increased by acceleration gradient based on the laundry amount, and then a main spinning stroke starts at the maximum rotation speed.

Thus, a spinning stroke is performed for distributing the laundry uniformly, considering the laundry amount.

However, in a related art spinning stroke it is difficult to sense the exact amount of the laundry in case that the laundry is tangled severely at the time when a spinning stroke is completed, although the related art spinning stroke is performed considering the laundry amount for enhancing an effect of laundry distribution.

Furthermore, since misjudgment of the laundry amount affects acceleration gradient, the laundry is not distributed uniformly and rolling of a drum and vibration noise of a drum may get worse during the spinning stroke. Thereby, it causes customer complaints and deteriorates product reliability.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a method for controlling a spinning stroke of a washing machine that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a method for controlling a spinning stroke of a washing machine, in which the laundry amount is sensed more accurately in a spinning stroke.

Another object of the present invention is to provide a method for controlling a spinning stroke of a washing machine, in which rolling of a drum and vibration noise of a drum is minimized in a spinning stoke.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for controlling a spinning stroke of a washing machine comprising steps of: judging a first value of the laundry amount based on a frequency of water re-supply counted in a rinsing stroke; measuring the time taken for a drum rotating before a spinning stroke to reach a preset speed once a rinsing stroke is completed; judging a second value of the laundry amount based on the measured time; determining a final value of the laundry amount based on the first and second value of the laundry amount; and starting a spinning stroke based on the spinning condition determined based on the final value of the laundry amount.

At that time the frequency of water re-supply is counted while performing a first one rinsing stroke after a rinsing stroke starts in the step of judging a first value of the laundry amount based on the number of water re-supply accounted in a rinsing stroke.

Also, the step of judging a first value of the laundry amount based on the frequency of water re-supply counted in a rinsing stroke comprises an (a) step of supplying washing water to a preset first water level once a rinsing stroke starts, a (b) step of rotating a drum leftward and rightward direction repeatedly once supplying water to the preset first water level is completed, a (c) step of sensing a water level periodically while rotating a drum leftward and rightward direction, a (d) step of re-supplying water to the preset first water level in case that the sensed water level is reduced lower than a preset second water level, and counting the frequency of water re-supply, and a (e) step of judging a first amount of the laundry based on the frequency of water re-supply counted by repeating the (b)-(d) steps after a rinsing stroke.

The step determining a final value of the laundry amount based on the first and second value of the laundry amount comprises steps of defining a criterion to judge a value of a first laundry amount by classifying the laundry amount into level I, II and III based on the frequency of water re-supply, and a criterion to judge a value of a second laundry amount by classifying the laundry amount into level A, B, C, D, E and F based on the time taken for a drum to reach a preset speed, judging a first and second laundry amount based on the counted frequency of water re-supply and the time taken for the drum to reach a preset speed, and determining a final value of the laundry amount corresponding to Chart 1 based on the first and second laundry amount judged by each criterion. CHART 1 SECOND AMOUNT OF LAUNDRY A B C D E F FIRST I SINGLE MINIMUM MINIMUN MINIMUM MINIMUM MAXIMUM AMOUNT PIECE OF II MINIMUM MINIMUM SMALL MIDIUM LARGE MAXIMUM LAUNDRY III SMALL SMALL SMALL MEDIUM LARGE MXIMUM VALUE (The laundry amount of I, II and III is I<II<III, and the laundry amount of A, B, C, D, E and F is A<B<C<D<E<F)

The step of starting a spinning stroke based on the spinning condition determined based on the final value of the laundry amount comprises steps of determining acceleration gradient corresponding to the final value of the laundry amount after having defined each acceleration gradient based on the laundry amount, and performing a spinning stroke by rotating the drum to a preset spinning speed based on the determined acceleration gradient.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is a sectional view illustrating key parts of a related art drum type washing machine.

FIG. 2 is a flow chart illustrating a method for controlling a spinning stroke of a washing machine according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIG. 1 illustrates a structure of a conventional drum type washing machine schematically, and FIG. 2 is a flow chart illustrating a method for controlling a spinning stroke of a washing machine according to the present invention.

A method for controlling a spinning stroke of a washing machine according to the present invention will be described with embodying a drum type washing machine of FIG. 1.

As shown in FIG. 1, a drum type washing machine includes a tub 2 mounted in a cabinet 1 and a drum 3 rotatably mounted on an inner center of the tub 2.

Furthermore, a motor 4 is provided at a first down side of the tub 2 and a motor pulley 41 is connected to the motor 4 by a shaft.

A drum shaft 32 is provided in rear of the drum 3, and a drum pulley 31 is provided in the drum shaft 32 for being connectedly in communication with the motor pulley 41 of the motor 4 by a belt 5 as a power transmitting element.

Also, a door 6 is coupled in front of the cabinet 1, and a gasket 7 is provided between the door 6 and the tub 2.

A spring 9 is provided between both sides of am upper surface of the cabinet 1 and an upper circumferential surface of the tub 2 for supporting the tub 2 to be lifted a predetermined distance from a bottom of the cabinet 1.

A damper is also provided between a downside of the cabinet and an outer circumferential surface of the tub 2 for dampening vibration generated from the rotation of the drum 3.

Referring to FIG. 2, a method for controlling a spinning stroke of a drum type washing machine with the above configuration will be described.

First, a user introduces the laundry into a drum 3 and sets a washing mode he/she wants so as to input a command starting an operation. Hence, washing water is supplied into the drum 3.

At that time, a motor 4 drives and the drum 3 is agitated leftward and rightward direction for performing a washing stroke (S10).

Next, once washing water used in a washing stroke is discharged outside after a washing stroke, a rinsing stroke starts. In a rinsing stroke, washing water not mixed with detergent is supplied and a drum 3 rotates for rinsing detergent and dirt remaining on the laundry.

At that time, the rinsing stroke is performed one or more times based on a washing mode selected by a user. While performing first one rinsing stroke, the amount of the laundry is sensed (S20).

More specifically, first, once washing water is supplied to a preset first water level H1 in the beginning of the first one rinsing stroke, a drum 3 is agitated leftward and rightward direction.

Once the laundry absorbs washing water by agitating the drum 3 leftward and rightward and a water level is getting lower to a second preset water level H2, agitating the drum 3 is stopped. After that, once water is re-supplied to the first preset water level, agitating the drum 3 starts again.

The above process is repeated, until the first one initial rinsing stroke is completed. During the above process the frequency of water re-supply is counted, and a first laundry amount is judged based on the counted frequency of water re-supply during the first one initial rinsing stroke (S30).

At that time, the criterion of judging the first laundry amount based on the frequency of the water re-supply is preset and programmed through related experiments.

Hence, once the rinsing stroke is completed, a spinning stroke is performed for dehydrating the laundry by means of centrifugal force generated in rotating the drum at a high speed.

The spinning stroke is classified into an initial spinning stroke rotating the drum 3 at a low speed and a main spinning stroke rotating the drum 3 at a high speed for dehydrating the laundry.

However, since a range of distributing the laundry as well as acceleration gradient having an effect of the maximum laundry distribution may be varied based on the laundry amount in rotating the drum 3, a final amount of the laundry should be judged for starting a main spinning stroke.

That is, the laundry amount is sensed for qualifying a balance condition suitable to a driving system of a washing machine including a motor 4, a belt 5, a drum pulley 31, a drum shaft 32, a motor pulley 41 so as to provide against vibration of the drum in a spinning stroke.

For that, a second amount of the laundry is judged by rotating the drum 3 at a low speed in the initial spinning stroke before the main spinning stroke (S40).

At that time, the laundry amount is sensed in a method of measuring the time taken for the drum 3 to reach a preset speed, for example, 70 rpm.

That is, the more laundry amount increases, the relatively longer time it takes for the drum to reach a preset speed. Thereby, a second amount of the laundry may be judged by the measured time.

A criterion of judging the second amount of the laundry based on the measured time taken for the drum to reach a preset speed is preset and programmed through related experiments.

Hence, a final amount of the laundry for starting a main spinning stroke is judged based on the first amount of the laundry sensed in the rinsing stroke and the second amount of the laundry sensed before the main spinning stroke (S50).

As shown in Chart 1, a criterion of judging the first amount of the laundry is defined as level I, II and III based on the frequency of water re-supply. A criterion of judging the second amount of the laundry is defined as level A, B, C, D, E and F based on the time taken for the drum to reach a preset speed. CHART 1 SECOND AMOUNT OF LAUNDRY A B C D E F FIRST I SINGLE MINIMUM MINIMUN MINIMUM MINIMUM MAXIMUM AMOUNT PIECE OF II MINIMUM MINIMUM SMALL MIDIUM LARGE MAXIMUM LAUNDRY III SMALL SMALL SMALL MEDIUM LARGE MXIMUM VALUE

In Chart 1, the laundry amount of I, II and III satisfies the condition of I<II<III, and the laundry amount of A, B, C, D, E and F satisfies the condition of A<B<C<D<E<F.

A final value of the laundry amount is determined by applying each value of the first and second laundry amount to Chart 1.

Next, when rotating the drum 3, acceleration gradient of spinning speed is applied based on the final amount of the laundry determined in the above step S50 so as to maximize an effect laundry distribution.

Rotating speed of the drum 3 is gradually increased by the acceleration gradient based on the final amount of the laundry, and a main spinning stroke starts at the maximum speed (S60).

Thus, considering the laundry amount sensed before a spinning stroke as well as the laundry amount sensed in a rinsing stroke for distributing the laundry within the drum uniformly, the final amount of the laundry for starting a spinning stroke is determined.

Industrial advantageous effects of a washing machine according to the above present invention will be described.

First, accuracy of sensing the laundry amount for starting a spinning stroke may be enhanced, because the final amount of the laundry is determined based on the laundry amount sensed just before a spinning stroke as well as the laundry amount sensed in a rinsing stroke.

Next, not only a laundry distribution effect may be consequently maximized but also vibration of the drum in a spinning stroke may be minimized, because the laundry amount is sensed more accurately.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. A method for controlling a spinning stroke of a washing machine comprising steps of: judging a first value of the laundry amount based on a frequency of water re-supply counted in a rinsing stroke; measuring the time taken for a drum rotating before a spinning stroke to reach a preset speed once a rinsing stroke is completed; judging a second value of the laundry amount based on the measured time; determining a final value of the laundry amount based on the first and second value of the laundry amount; and starting a spinning stroke based on the spinning condition determined based on the final value of the laundry amount.
 2. The method for controlling a spinning stroke of a washing machine of claim 1, wherein the frequency of water re-supply is counted while performing a first one rinsing stroke after a rinsing stroke starts in the step of judging a first value of the laundry amount based on the number of water re-supply accounted in a rinsing stroke.
 3. The method for controlling a spinning stroke of a washing machine of claim 1, wherein the step of judging a first value of the laundry amount based on the frequency of water re-supply counted in a rinsing stroke comprises, an (a) step of supplying washing water to a preset first water level once a rinsing stroke starts, a (b) step of rotating a drum leftward and rightward direction repeatedly once supplying water to the preset first water level is completed, a (c) step of sensing a water level periodically while rotating a drum leftward and rightward direction, a (d) step of re-supplying water to the preset first water level in case that the sensed water level is reduced lower than a preset second water level, and counting the frequency of water re-supply; and a (e) step of judging a first amount of the laundry based on the frequency of water re-supply counted by repeating the (b)˜(d) steps after a rinsing stroke.
 4. The method for controlling a spinning stroke of a washing machine of claim 1, wherein the step of determining a final value of the laundry amount based on the first and second value of the laundry amount comprises steps of, defining a criterion to judge a value of a first laundry amount by classifying the laundry amount into level I, II and III based on the frequency of water re-supply, and a criterion to judge a value of a second laundry amount by classifying the laundry amount into level A, B, C, D, E and F based on the time taken for a drum to reach a preset speed, judging a first and second laundry amount based on the counted frequency of water re-supply and the time taken for the drum to reach a preset speed, and determining a final value of the laundry amount corresponding to Chart 1 based on the first and second laundry amount judged by each criterion. CHART 1 SECOND AMOUNT OF LAUNDRY A B C D E F FIRST I SINGLE MINIMUM MINIMUN MINIMUM MINIMUM MAXIMUM AMOUNT PIECE OF II MINIMUM MINIMUM SMALL MIDIUM LARGE MAXIMUM LAUNDRY III SMALL SMALL SMALL MEDIUM LARGE MXIMUM VALUE (The laundry amount of I, II and III is I < II < III, and the laundry amount of A, B, C, D, E and F is A < B < C < D < E < F)


5. The method for controlling a spinning stroke of a washing machine of claim 1, wherein starting a spinning stroke based on the spinning condition determined based on the final value of the laundry amount comprises steps of, determining acceleration gradient corresponding to the final value of the laundry amount after having defined each acceleration gradient based on the laundry amount, and performing a spinning stroke by rotating the drum to a preset spinning speed based on the determined acceleration gradient. 